“Ms Roderick, from Merthyr Tydfil, was transferred to Prince Charles Hospital from Ysbyty Cwm Cynon with serious injuries which are being treated as unexplained.

“At this stage there is no confirmed link between the injuries and her death.

“Four people are assisting officers with their enquiries.”

The pensioner from Abercanaid, Merthyr Tydfil, was pronounced at the town’s Prince Charles Hospital following a stay at Ysbyty Cwm Cynon, Mountain Ash.

Ten members of staff employed by Cwm Taf University Health Board were initially suspended as a “precautionary measure”.

But the health board have today lifted the suspensions on six of those workers. The remaining four suspensions will be reviewed as the investigation proceeds.

Allison Williams, health board chief executive, said: “It is with great sadness that I recognise that patients, relatives and local people will understandably have concerns about the ongoing investigation and media coverage surrounding Ysbyty Cwm Cynon.

“Cwm Taf University Health Board takes the care and safety of its patients extremely seriously.

“As soon as staff identified that there was a problem with the patient concerned, they acted quickly and appropriately.

“We are continuing to work with the police to do everything we can to get to the bottom of what happened.

“We would like to emphasise that there is no suggestion that any other patients have been affected.

“However, if relatives have any concerns about the care of their loved ones they are encouraged to talk to the ward staff who can arrange for them to speak with a senior member of the Health Board team if that would be helpful.

“On behalf of the whole Board, I extend my heartfelt condolences to the family at this difficult time.”

Neighbours described Mrs Roderick as a “lovely lady” who had lived at Donald Street, Abercanaid, all her life.

One neighbour, who did not want to be named, said: “It’s very sad. I have known her all my life.

“She was a lovely lady. Everyone here is very sad about what has happened.”